Partial corneal conjunctival contact lens

ABSTRACT

A contact lens system, including a peripheral conjunctival cover portion including a shell curved and sized to substantially overly a conjunctiva of an eye. The conjunctival cover portion defines a full thickness central opening therethrough. The central opening is positioned within the conjunctival cover and sized to expose at least a portion of a cornea of the eye. The contact lens system further includes a central contact lens portion that is substantially equivalent in size to the central opening and positioned or positionable at the central opening.

FIELD OF THE INVENTION

The invention relates generally to the field of contact lenses and tothe field of medication delivery by inserts.

BACKGROUND OF THE INVENTION

Contact lenses have been in existence for many decades. Early contactlenses were made of glass or rigid plastic such aspolymethylmethacrylate (PMMA). Early contact lens designs were quitelarge and referred to as scleral or haptic lens. Scleral or hapticcontact lens designs cover the cornea completely as well as covering alarge portion of the conjunctiva or sclera of the eye. The sclera is thestructural white of the eyeball while the conjunctiva is a transparenttissue which overlies the sclera as well as covering the backside of theeye lids. Early contact lens designs were made of rigid, largely oxygenimpermeable polymers as discussed above or a very few of glass. Becausecornea physiology was poorly understood at the time these lenses weremade, they often cause great discomfort and negative effect on thecorneal health.

As time went by, in the 1950's, hard contact lenses made ofpolymethylmethacrylate became much smaller having a diametersignificantly smaller than that of the cornea. Hard corneal contactlenses were more comfortable and less physiological damaging thanscleral or haptic lenses, but only marginally so. Hard contact lensesstill significantly deprived the cornea of a necessary oxygen supplyfrom atmospheric oxygen to maintain good corneal health and weredifficult to adapt to. In the 1970s, so called soft corneal contactlenses became available. Soft contact lenses generally are larger thanhard corneal contact lenses having a diameter approximating that of thecornea, somewhat larger than the cornea or somewhat smaller than thecornea. Soft contact lenses are generally made of hydrophilic polymers,such as polyhydroxy ethylmethacrylate (poly HEMA), that absorbsubstantial amounts of water, saline solution or the tear film. Softcontact lenses also provided improved comfort due to their permeabilityto oxygen and due to their more flexible nature. Later still, so calledgas-permeable contact lenses became available. Gas permeable rigidcontact lenses are similar in size and structure to hard corneal contactlenses but are made of rigid oxygen permeable polymers that allow oxygenand other gases to pass through the material of the contact lens toprovide improved corneal health. Generally, rigid contact lenses providesharper vision than soft contact lenses though this is not universallytrue.

Hard contact lenses are well as scleral or haptic contact lenses weresometimes fenestrated. That is, tiny holes were drilled or otherwiseformed through the rigid contact lens material in an effort to improvetear exchange under the contact lens or to provide a greateravailability of oxygen through the contact lens. Fenestration wasgenerally not a very successful technique. Fenestrations, however, wereuniformly tiny holes generally much smaller than one millimeter indiameter, occasionally multiple fenestrations were present.

All contact lenses known to the applicant provide substantially orcomplete coverage of the cornea of the eye.

Drug delivery inserts are also known to exist. Drug delivery inserts aresmall containers into which drugs or pharmaceuticals are placed orabsorbed that exist in several different forms. Subpalpebral drugdelivery inserts are generally intended to be inserted behind the eyelid in the conjunctival fornices and to gradually release a desiredmedication to provide a slow, continuous supply of drug to the eye.Subpalpebral drug delivery inserts generally have suffered from beinguncomfortable for the patient to tolerate and subject to be accidentallydislodged from the eye by rubbing of the eye or other movements. Inaddition, subpapebral drug delivery inserts sometimes cause irritationof the conjunctiva or the eye lids.

Another variety of drug delivery insert is intended to be surgicallyinserted within the globe of the eye to gradually leach out a steadysupply of a desired drug into the intraocular environment. Intraoculardrug delivery inserts are less often used due to their relativelyinvasive nature.

Generally, drug delivery inserts whether subpalpebral or intraocularhave contained a single drug.

Dry eye syndrome is one of the most commonly treated eye problems in theUnited States. Dry eye syndrome is also known as keratitis sicca,keratoconjunctivitis sicca (KCS) xerophthalmia, and lacrimalinsufficiency. It is estimated that over ten million Americans and 30million persons worldwide suffer from dry eye syndrome.

For a large fraction of dry eye patients, dry eye syndrome createsdiscomfort or annoyance. For those severely afflicted, dry eye syndromecan be debilitating and, in some circumstances, even sight-threatening.In extremely severe cases, dry eye syndrome can even lead to the loss ofan eye.

Dry eye syndrome typically results from deficiency in the quality orquantity of tears produced by the patient. Precorneal tear film hastraditionally been considered to have a three-layered structure. Closestto the cornea lies the mucin, or mucus, layer. The mucin layer providesan interface between the corneal epithelium and the remainder of thetear film. Overlying the mucin layer is the watery aqueous layer, whichis the thickest layer of the three. The outermost layer of theprecorneal tear film is the lipid layer. The lipid layer is an oily filmthat reduces evaporation from the aqueous layer beneath it.

The middle aqueous layer provides moisture to the corneal tissue,carries important nutrients, and serves to remove metabolic wasteproduced by the cornea. Deficiency in any of the three layers of theprecorneal tear film can result in complaints of dry, gritty feeling orburning eyes.

The mucin that forms the mucin layer, nearest the cornea, is secreted bygoblet cells in the conjunctiva. The conjunctiva is the transparenttissue that covers the sclera and the backside of the eyelids. The mucinlayer functions to decrease surface tension of the tear film. Inaddition, the cornea itself is hydrophobic. Without the mucin layer toprovide a bridge between the cornea and the aqueous layer, the aqueouslayer would bead up and allow dry spot formation on the cornea.

The aqueous layer is secreted primarily by the glands of Wolfring andKrause located in the eyelid margin. The aqueous layer helps provide anoptically smooth, transparent surface to the precorneal tear film. Thelipid layer is secreted by the meibomian glands, and the glands of Zeissand Moll. The glands of Zeiss and Moll are also located at the eyelidmargin.

Blinking is essential to maintenance of the precorneal tear film. Duringeach blink, the eyelid wipes over the surface of the cornea, smoothingthe mucin layer and spreading the overlying aqueous and lipid layers toprovide a completely wetted surface. In between blinks, the tear filmthins due to evaporation of the aqueous layer. If evaporation isexcessive, dry spots may form on the surface of the cornea.

Deficiency, or imperfect quality, of any of the three component layerscan lead to dry eye symptoms. Many systemic and external factors cancontribute to dry eye syndrome. For example, Sjogren's syndrome isassociated with arthritic diseases in combination with dry eye and drymouth. Deficiency of Vitamin A, use of oral contraceptives andenvironmental factors can all contribute to dry eye syndrome.Inflammation has also been demonstrated to contribute to dry eye.

Research into the natural history of dry eye syndrome suggests that thedisease progresses through four stages. Each stage is a consequence ofthe preceding stage. The stages are:

-   -   1. Loss of water from the aqueous layer of the tear film leading        to an increase in the tear film osmolarity;    -   2. Loss of conjunctival goblet cells and decreased corneal        glycogen;    -   3. Increased loss of corneal squamous epithelial cells;    -   4. Destabilization of the interface between the corneal surface        and the tear film.

Either decreased secretion of tear film components or increasedevaporation lead to increased tear film osmolarity and the followingstages that lead to eventual corneal decompensation and the seriousconsequences of dry eye syndrome.

The adnexa of the eye may also be involved in dry eye syndrome. Theadnexa of the eye include the structures surrounding the eye such as theeyelids, eye lashes, the tear drainage and tear production structures.Blepharitis commonly contributes to dry eye syndrome. Blepharitistypically results from bacterial infection of the tiny glands in themargin of the eyelid. These glands include the glands of Zeiss, Moll andWolfring as well as the meibomian glands. Most commonly, the affectedglands are the meibomian glands. In bacterial blepharitis, bacterialinfection causes the meibomian glands to become plugged, and thus not beable to produce a normal lipid layer to contribute to the tear film.Some bacteria that infect the glands also secrete exotoxins that seepout of the glands into the eye and injure the corneal epithelium.

Treatments of dry eye syndrome vary depending upon the type ofpresentation. The most common treatment for dry eye syndrome is the useof artificial tear supplements to provide additional moisture andlubrication to the corneal surface. Artificial tear eye drops are placedon the eye by the patient. Artificial tear supplements must be usedregularly and often to be effective.

Lubricant ointments may also be employed. Ointments are usually used atbedtime because they tend to be messy and blur vision. For somepatients, even the use of ointments is not sufficient to provide comfortduring sleep.

Tears drain from the eye through the lacrimal drainage system. Tinyopenings at the nasal corner of each upper and lower eyelid are calledthe lacrimal puncta. The lacrimal puncta lead into ducts that drain intothe nasopharynx.

One treatment for dry eye syndrome is to partially or completely closeone or more lacrimal puncta to reduce tear outflow into the lacrimaldrainage apparatus. Traditionally, this closure was accomplishedsurgically or by cautery. In the last decade, however, temporary andpermanent punctal occlusion plugs have been utilized.

Permanent punctal plugs are typically made from surgical silicone;temporary plugs are generally made of soluble collagen. Collagen plugsdissolve over a period of days and are helpful in diagnosis.

Punctal plugs are placed into the lacrimal puncta, or lacrimal drainageducts. The plugs impede the outflow of tears from the eye. This approachslows the outflow of tears and retains them in the eyes longer, oftenrelieving symptoms. Punctal plugs have the distinct advantage of beingreadily removable and avoid the issues of scar formation.

Blepharitis is sometimes treated by the use of antibiotic medications.Another important treatment for blepharitis is the application of warmsoaks and lid scrubs. In this form of treatment, the patient applies awarm wet washcloth to the eyelids for a period of time to providehumidity, warmth and to help soften blockage of and restore flow fromthe meibomian glands. Lid scrubs are practiced by taking a mild,nonirritating soap and vigorously scrubbing the eyelid margins with theyeyes closed, so as to massage the meibomian glands and increaseproduction. The surfactant helps to dissolve the greasy blockage of themeibomian glands.

Patients who have severe dry eye syndrome often suffer disrupted sleepbecause they cannot go for longer than an hour or so without applyingtear supplements to the eyes. This can lead to pronounced sleepdeprivation and a consequent reduction in quality of life.

A variety of researchers have been seeking other medicinal treatmentsfor dry eye syndrome. Largely, this research is directed atpharmaceutical efforts to increase tear production.

Accordingly, there is still room for improvement in the contact lensrelated.

SUMMARY OF THE INVENTION

A partial corneal conjunctiva contact lens according to an exampleembodiment of the invention includes an annular conjunctival cover incombination with a central lens portion. The central lens portion may bephysically separate and used along with the annular conjunctival coveron the eye or may be physically joined to the annular conjunctivalcover. The central lens may be of size somewhat larger than a centralopening of the annular conjunctival cover and overlap the annularconjunctival cover either anteriorly or posteriorly when the combinationof central lens portion and than a central opening of the annularconjunctival cover is applied to the eye. Alternately, the central lensmay be somewhat smaller in diameter than the central opening of theannular conjunctival cover and may be positioned within the opening whenthe central lens and annular conjunctival cover are applied to the eye.In this case the central lens may be a separate structure from theconjunctival cover or may be physically coupled to the annularconjunctival cover.

For the purposes of this application, reference may be made to thecentral lens portion or central contact lens portion being substantiallyequivalent in size to the central opening in the conjunctival cover.This term shall be defined as the central lens having an outsidediameter equal to the inside diameter of the central opening or varyingby plus or minus five millimeters.

According to another example embodiment the annular conjunctival coverand the central lens portion are joined as an integral unit withcoupling members securing the central lens portion to the annularconjunctival cover and passages between the central lens portion and theannular conjunctival cover permitting fluid flow. The central lensportion may be somewhat larger than a central opening of the annularconjunctival cover and joined to the annular conjunctival cover tooverlap the annular conjunctival cover either anteriorly or posteriorly.Thus, the central lens portion may overly or underlie the annularconjunctival cover when the central lens portion is placed on the eye.Alternately, the central lens may be somewhat smaller in diameter thanthe central opening of the annular conjunctival cover and be coupledwithin the opening of the annular conjunctival cover. Fluid patentpassages that permit the flow of tears between the central lens portionand the annular conjunctival cover are present in each of the abovedescribed integral units.

The annular conjunctival cover in combination with the central lensportion is expected to facilitate tear pumping from the posterior spacebetween the annular conjunctival cover and the central lens portion andthe eye to the anterior surface of the annular conjunctival cover andthe central lens portion.

According to another embodiment, the invention includes a method oftreating or correcting a patient including applying a conjunctival coverhaving an opening centrally located therein to the eye and then applyinga central contact lens portion over, under or within the opening in theconjunctival cover.

According to other embodiments of the invention, the central lensportion is coupled to the annular conjunctival cover overlying,underlying or within the central opening at multiple locations. Forexample, the central lens portion may be coupled adjacent the centralopening of the annular conjunctival cover by three coupling members.According to another embodiment, the central lens portion may be coupledto the annular conjunctival cover by four or more coupling members. Thecoupling members may be arranged symmetrically around or adjacent theperimeter of the central lens portion or may be arranged asymmetrically.For example, three coupling members may be arranged at 120 degree anglesaround the perimeter of the central lens portion. According to anotherexample embodiment, four coupling members can be arranged at 90 degreesintervals around the perimeter of the central lens portion. According toother embodiments of the invention, coupling members may beasymmetrically arranged. For example, in one embodiment, three couplingmembers may be arranged at 3 o'clock, 12 o'clock and 9 o'clock which twoadditional coupling members may be arranged at the 4 o'clock and 8o'clock positions. The arrangement of coupling members, whethersymmetrical or asymmetrical may have an effect on the pumping of tearsas the blinking eyelid moves, compresses and releases the cornealconjunctival contact lens system.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic depiction of a prior art scleral contact lens;

FIG. 2 is a schematic depiction of an annular conjunctival cover appliedto an eye according to an example embodiment of the invention;

FIG. 3 is a is a schematic depiction of an elliptical annularconjunctival cover applied to an eye according to an example embodimentof the invention;

FIG. 4 is a schematic depiction of an elliptical annular conjunctivalcover isolated from the eye according to an example embodiment of theinvention;

FIG. 5 is a schematic depiction of a conjunctival cover having an innerring, an outer ring and a segmented structure according to an exampleembodiment of the invention;

FIG. 6 is a schematic depiction of an annular conjunctival coveraccording to an example embodiment of the invention;

FIG. 7 is a schematic depiction of a conjunctival cover having a partialinner ring, an outer ring and a segmented structure according to anexample embodiment of the invention;

FIG. 8 is a schematic depiction of a conjunctival cover having a drugreservoir to support drug delivery capability according to an exampleembodiment of the invention;

FIG. 9 is a schematic depiction of a conjunctival cover having multipledrug reservoirs to support drug delivery capability according to anexample embodiment of the invention;

FIG. 10 is a schematic depiction of a conjunctival cover having multiplelayers according to an example embodiment of the invention;

FIG. 11 is a cross-sectional view of an embodiment of the invention insitu on an eye including an annular conjunctival cover and a centrallens portion overlying the annular conjunctival cover according to anexample embodiment of the invention;

FIG. 12 is a cross-sectional view of an annular conjunctival cover insitu on an eye and a central lens portion underlying the annularconjunctival cover according to an example embodiment of the invention;

FIG. 13 is a cross-sectional view of an annular conjunctival cover and acentral lens portion situated within the opening of the annularconjunctival cover in situ on an eye according to an example embodimentof the invention;

FIG. 14 is a cross-sectional view of an annular conjunctival cover andan attached central lens portion underlying the annular conjunctivalcover in situ on an eye according to an example embodiment of theinvention;

FIG. 15 is a cross-sectional view of an annular conjunctival cover withan attached central lens portion overlying the annular conjunctivalcover in situ on an eye according to an example embodiment of theinvention;

FIG. 16 is a schematic plan view of an annular conjunctival cover withan attached central lens portion secured to the annular conjunctivalcover via four attachment numbers according to an example embodiment ofthe invention;

FIG. 17 is a schematic plan view of an annular conjunctival cover and anattached central lens portion coupled to the annular conjunctival coverby three symmetrically located attachment members according to anexample embodiment of the invention;

FIG. 18 is a plan view of annular conjunctival cover and an attachedlens portion attached to the annular conjunctival cover by fiveasymmetrically located attachment members according to an exampleembodiment of the invention; and

FIG. 19 is a plan view of annular conjunctival cover and an attachedlens portion attached to the annular conjunctival cover wherein the lensportion neither underlies nor overlies the conjunctival cover.

DETAILED DESCRIPTION

Referring to FIGS. 11-18, corneal conjunctival contact lens system 100generally includes conjunctival cover 102 and central lens portion 104.

Conjunctival cover 102 is generally as described elsewhere in thisapplication. Accordingly, conjunctival cover 102 of corneal conjunctivalcontact lens system 100 may take the form of conjunctival shield 20,elliptical conjunctival shield 46, dual ring conjunctival shield 50,partial inner ring conjunctival shield 66, drug delivery conjunctivalshield 82 or multilayer conjunctival shield 92.

Accordingly, example embodiments of corneal conjunctival contact lenssystem 100 include uncoupled corneal conjunctival lens system 106 andcoupled corneal conjunctival lens system 108.

Referring particularly to FIGS. 11-13, uncoupled corneal conjunctivallens system 106 includes: conjunctival cover 102 and central lensportion 104 which are physically separate structures.

Referring to FIG. 11, uncoupled corneal conjunctival lens system 106 mayinclude overlying central lens portion 110. According to thisembodiment, conjunctival cover 102 is placed on the eye first, followedby overlying central lens portion 110. Overlying central lens portion110 includes: bridging portion 112 and overlying portion 114. Overlyingcentral lens portion 110 is movable with blinking relative toconjunctival cover 102. Accordingly, the margin between bridging portion112 and overlying portion 114 is somewhat variable. Bridging portion 112generally bridges over central opening 116 of conjunctival cover 102.Overlying central lens portion 110 may be similar in design to soft orrigid contact lens known to those of ordinary skill in the art.Overlying central lens portion 110 may also include features thatdistinguish bridging portion 112 from overlying portion 114. Overlyingcentral lens portions 110 also generally includes a central optical zone118 and a peripheral zone 120. Optical zone 118 may or may not coincidewith bridging portion 112. Peripheral zone 120 may or may not coincidewith overlying portion 114.

Referring now to FIG. 12, uncoupled corneal conjunctival lens system 106including underlying central lens portion 122 is depicted. Underlyingcentral lens portion includes opening portion 124 and underlying portion126. Underlying central lens portion 122 also includes optical zone 128and peripheral zone 130 similar to contact lens known to those ofordinary skill in the art. Optical zone 128 does not necessarilycoincide with opening portion 124 nor does peripheral zone 130necessarily coincide with underlying portion 126 though they maycoincide.

Referring to FIG. 13 another embodiment of uncoupled cornealconjunctival lens system 106 is depicted. In the depicted embodiment,intraopening central lens portion 132 is sized to be somewhat smallerthan central opening 134 of conjunctival cover 102. Intraopening centrallens portion 132 is sized to be smaller than central opening 134.Intraopening central lens portion 132 may be similar in structure anddesign to conventional soft or rigid contact lens known to those ofordinary skill in the art. Intraopening central lens portion 132generally includes optical zone 136 and peripheral zone 138.

Referring now to FIGS. 14-19, example embodiments of coupled cornealconjunctival lens system 108 are depicted. The depicted embodimentsinclude conjunctival cover portion 140 and coupled central lens portion142.

Referring now to FIG. 14, posterior coupled corneal conjunctival lens144 includes conjunctival cover 102 and posterior central lens portion146. Referring to FIGS. 14 and 16-18, posterior central lens portion 146is attached to conjunctival cover 102 by attachment members 148. Asdepicted in FIGS. 16-18, attachment members 148 may be arrangedsymmetrically or asymmetrically. Attachment members 148 may also vary insize and shape from each other.

Referring now to FIG. 15, anterior coupled corneal conjunctival lens 150is depicted. Anterior coupled corneal conjunctival lens 150 includesanterior central lens portion 152 coupled to conjunctival cover portion154. Similar to the above described example embodiment, attachmentmembers 148 may be oriented symmetrically or asymmetrically as depictedin FIGS. 16-18. Further, attachment members 148 may vary in size andshape relative to one another.

Referring now to FIG. 19, another embodiment of coupled cornealconjunctival lens system 108 is depicted. In the depicted embodiment,coupled central lens portion 142 is coupled to conjunctival coverportion 140 by attachment members 148. Attachment members 148 areseparated by and adjacent to openings 156.

Referring generally to FIG. 1-10, conjunctival cover 20 according to anembodiment of the invention, generally includes annular shell 22presenting central opening 24. Annular shell 22 is formed of ahydrophilic or non-hydrophilic flexible material similar to those usedin the manufacture and construction of soft contact lenses. Conjunctivalcover 20 is utilized in relation to an eye 26. Eye 26 generally includessclera 28, conjunctiva 30, cornea 32, limbus 34 and eyelids 36. Thesclera is the structural white portion of the eye that forms themajority of the eyeball. Conjunctiva 30 overlies the sclera and includespalpebral conjunctiva 40 and bulbar conjunctiva 42. Palpebral conjuctiva40 and bulbar conjuctiva 42 meet at fornices 44. Cornea 32 is the clearfront part of the eye and is generally dome shaped in structure. Limbus34 is the juncture between the edge of the cornea 32 and sclera 28.Conjunctival cover 20 generally covers bulbar conjuctiva 42 whileleaving all or a portion of cornea 32 exposed. For this purpose, centralopening 24 is positioned to generally coincide with cornea 32. Annularshell 22 of conjunctival cover 20 may be sized to extend into fornices44 or may be smaller in size.

Referring to FIGS. 3 and 4, another embodiment of conjunctival cover 20is elliptical conjunctival cover 46. Elliptical conjunctival cover 46includes annular shell 22 having generally elliptical peripheral margin48. Elliptical conjunctival cover 46 may be sized so that ellipticalperipheral margin 48 is generally coincident with eyelid margins 38.Accordingly, elliptical peripheral margin 48 may extend partially undereyelid margins 38 or may be slightly smaller than the space bounded byeyelid margins 38 when eye 26 is open.

Referring now to FIG. 5, another embodiment of conjunctival cover 20 isdepicted. Dual ring conjunctival cover 50 generally includes inner ring52, outer ring 54, nasal cover portion 56 and temporal cover portion 58.Inner ring 52 approximates the corneal diameter being slightly larger orslightly smaller than the limbus. Outer ring 54 is larger than innerring 52 and may be sized to extend partially or completely into fornices44. Inner ring 52, outer ring 54, nasal cover portion 56 and temporalcover portion 58 together define arcuate openings 60. Arcuate openings60 include superior arcuate opening 62 and inferior arcuate opening 64.Inner ring 52, outer ring 54, nasal cover portion 56 and temporal coverportion 58 may be integrally formed, for example, by a molding processor may be overmolded or otherwise assembled of separate structures.

Referring now to FIG. 7, another embodiment of conjunctival cover 20 isdepicted. Partial inner ring conjunctival cover 66 generally includesouter ring 68, nasal inner ring segment 70, temporal inner ring segment72, nasal cover portion 56 and temporal cover portion 58. Thesestructure together define central opening 74 which includes superioropening portion 76, inferior opening portion 78 and central openingportion 80. Accordingly, when placed upon the eye, partial inner ringconjunctival cover 66 generally covers the nasal and temporalconjunctiva while not covering the superior and inferior conjunctivawhich are covered by eyelids 36.

Conjunctival cover 20 may also include other fenestrations beyond thoseidentified herein.

Referring now to FIG. 8, another embodiment of conjunctival cover 20 isdepicted. Drug delivery conjunctival cover 82 can be similar instructure to any of the above described conjunctival covers 20 but isadapted for drug delivery.

According to an embodiment depicted in FIG. 8, drug deliveryconjunctival cover 82 includes first drug reservoir 84, second drugreservoir 86 and third drug reservoir 88. Drug delivery conjunctivalcover 82 may include one or more drug reservoirs 90. Drug reservoirs 90may be formed as cavities within drug delivery conjunctival cover 82which are bounded by a material that is bio-absorbable or bio-degradablein the eye environment. A wall thickness of first drug reservoir 84,second drug reservoir 86 and third drug reservoir 88 may vary in orderto facilitate timed release of drug dosages. The first drug reservoirmay have a thinner wall that is breached by bio-absorption orbiodegradation sooner than the thicker walls of second drug reservoir 86or third drug reservoir 88.

Drug delivery conjunctival cover 82 may also be formed of a hydrophilicmaterial that absorbs an aqueous solution of a drug to be released forlater diffusion into the ocular conjunctival environment. Thus, drugdelivery conjunctival cover 82 may be formed of a poly-HEMA or anotherhydrophilic material known to those skilled in the contact lens arts.

Referring now to FIG. 9, another embodiment of conjunctival cover 20 isdepicted in cross-section. Multi-layer conjunctival cover 92 includes atleast first layer 94 and second layer 96. Multi-layer conjunctival cover92 may have two or more layers of similar or different constructionmaterials.

Drugs to be delivered by drug delivery conjunctival cover 82 may includebut are not limited to antibiotics, steroids, glaucoma medications,antiviral medications, antifungal medications, NSAIDs, surfacelubricants and anti-inflammatories such as cyclosporine.

Drug delivery conjunctival cover 82 may also be utilized to delivernano-technology substances into the eye.

According to another example embodiment the invention includes a methodof treating an eye, including applying an annular conjunctival cover tothe eye by retracting the eyelids and placing the annular conjunctivalcover on a bulbar conjunctiva of the eye while leaving a cornea of theeye substantially uncovered; and releasing the eye lids.

The method may further include incorporating a drug into the annularconjunctival cover prior to application.

The method may further include incorporating the drug into the annularconjunctival cover by exposing the annular conjunctival cover to thedrug in solution or suspension such that the drug is absorbed into theannular conjunctival cover.

The method may further include incorporating the drug into the annularconjunctival cover by inserting the drug into a drug reservoirincorporated in the annular conjunctival cover.

The method may further include inserting multiple drugs into multipleseparate drug reservoirs incorporated in the annular conjunctival cover.

According to another embodiment, the invention includes a method oftreating an eye including applying a conjunctival cover portion 102 toan eye and applying a central contact lens portion 104 to an eye andfacilitating tear pumping by the relationship between the conjunctivalcover portion 102 and central contact lens portion 104.

According to another embodiment of the invention, the method may bepracticed wherein the central contact lens portion 104 is structurallyseparate from the conjunctival cover 102 and the method may furtherinclude applying the central contact lens portion 104 to the eye priorto and partially underlying conjunctival cover 102.

According to another embodiment of the invention, the method may bepracticed wherein the central contact lens portion 104 is structurallyseparate from the conjunctival cover 102 and wherein the method furtherincludes applying the central contact lens portion 104 to the eye afterand partially overlying the conjunctival cover 102.

According to another embodiment of the invention, the method may bepracticed wherein the central contact lens portion 104 is structurallyjoined to the conjunctival cover 102 and the method further includesapplying the central contact lens portion 104 and the conjunctival cover102 to the eye as a unit.

According to another embodiment of invention, the central lens portionis structurally joined to the conjunctival cover and the method furtherincludes selecting an arrangement of attachment members 148 joining thecentral contact lens to the conjunctival cover to be symmetricallyarranged whereby tear pumping is facilitated.

According to another embodiment of the invention, central contact lensportion 104 is structurally joined to conjunctival cover 102 and themethod further includes selecting attachment members 148 to be arrangedto join central contact lens 104 to conjunctival cover 102asymmetrically whereby tear pumping is facilitated.

In operation, various embodiments of conjunctival cover 20 are appliedto conjunctiva 30 in a similar fashion to the application of a softcontact lens or a sclera contact lens. Various embodiments ofconjunctival cover 20 may be applied to eye 26 by the patient or by ahealth care professional. Eyelids 36 are pulled open by using thefingers near the eyelids margins 38 and conjunctival cover 20 is placedupon the eye at least partially covering the conjunctiva 30. Asdiscussed above, various embodiments of conjunctival cover 20 maypartially or completely cover the conjunctiva 30 while partially orcompletely exposing the cornea 32. Various embodiments of conjunctivalcover 20 trap mucin and other tear film components between conjunctivalcover 20 and conjunctiva 30. The tear film also covers the externalsurface of conjunctival cover 20. Upon blinking, eyelids 36 and inparticular eyelid margins 38 pass over conjunctival cover 20 and bothwipes tear film components on the surface of conjunctival cover 20 ontocornea 32 and also squeezes or massages tear film components betweenconjunctival cover 20 and conjunctiva 30 onto cornea 32.

Elliptical conjunctival cover 46 covers conjunctiva 30 substantiallybetween eyelid margins 38. Dual ring conjunctival cover 50 is placed oneye 26 so that nasal cover portion 56 covers nasal palpebral conjunctiva40 while temporal cover portion 58 covers the temporal bulbarconjunctiva 42.

Partial inner ring conjunctival cover 66 is placed on eye 26 so thatnasal cover portion 56 covers nasal bulbar conjunctiva 40 while temporalcover portion 58 covers temporal bulbar conjunctiva 42.

Drug delivery conjunctival cover 82 is placed on eye 26 where drugsabsorb into drug delivery conjunctival cover 82 diffuse out into eye 26and surrounding structures.

In the case of drug delivery conjunctival cover 82 having first drugreservoir 84 and optionally second drug reservoir 86 and third drugreservoir 88, drug reservoirs 90 dissolve at planned rate to providetime release of contained drugs into the eye.

Referring to FIGS. 11-19, in operation, corneal conjunctival contactlens system 100 is applied on the eye. Referring to FIG. 11, uncoupledcorneal conjunctival lens system 106, for example, may be applied byfirst applying conjunctival cover 102 followed by central lens portion104.

According to another embodiment, uncoupled corneal conjunctival lenssystem 106 can be applied as in FIG. 12. Accordingly, central lensportion 104 is applied to the cornea of the eye followed by conjunctivalcover 102.

Referring to FIG. 13, according to another example embodiment, uncoupledcorneal conjunctival lens system 106 may be applied to the eye byapplying either conjunctival cover 102 or central lens portion 104 tothe eye first followed by the other of conjunctival cover 102 andcentral lens portion 104.

Referring again to FIG. 11, overlying portion 114 of central lensportion 104 extends beyond central opening 116 and thus overliesconjunctival cover 102.

Referring again to FIG. 12, underlying central lens portion 122 ofcentral lens portion 104 underlies conjunctival cover 102 according tothis example embodiment. In any of the discussed embodiments, opticalzone 128 generally overlies an optical axis of the eye while peripheralzone 130 is peripheral to optical zone 128.

Referring again particularly to FIG. 13, intraopening central lensportion 132 is sized to fit within central opening 134. Accordingly, agap exists between intraopening central lens portion 132 andconjunctival cover 102 according to this embodiment of the invention.

Referring now to FIGS. 14-19, coupled corneal conjunctival lens system108 is applied to the eye as a unit.

Referring to FIG. 14, posterior coupled corneal conjunctival lens 144 isapplied to the eye as a unit. As the eyelid passes over, conjunctivalcover portion 140 and coupled central lens portion 142, it is expectedthat the tears will be tears are pumped from beneath conjunctival coverportion 140 between conjunctival cover portion 140 and coupled centrallens portion 142 and then out to the anterior surface.

Referring to FIG. 15, anterior coupled corneal conjunctival lens 150 isapplied to the eye as a unit. As the eyelids pass over anterior centrallens portion 152 and conjunctival cover portion 154, it is expected thatthe tears will be pumped from beneath conjunctival cover portion 154between anterior central lens portion 152 and conjunctival cover portion154 onto the anterior surface of anterior central lens portion 152 andconjunctival cover portion 154.

Referring now to FIG. 19, coupled corneal conjunctival lens system 108as in the depicted embodiment, is applied to the eye as a unit. Coupledcentral lens portion 142 is coupled to conjunctival cover portion 140 byattachment members 148. Openings 156 are located adjacent to and betweenattachment members 148.

It is expected that the movement of eyelids during blinking will pumptears from beneath conjunctival cover portion 140 and coupled centrallens portion 142 through openings 156 to the anterior of coupled centrallens portion 142 and conjunctival cover portion 140. It is alsoexpected, in the case of uncoupled corneal conjunctival lens system 106,that similar tear pumping will occur.

According to embodiments of the invention, conjunctival cover 102 andcentral lens portion 104 may be removed in a similar fashion to softcontact lenses.

The present invention may be embodied in other specific forms withoutdeparting from the spirit of the essential attributes thereof;therefore, the illustrated embodiments should be considered in allrespects as illustrative and not restrictive, reference being made tothe appended claims rather than to the foregoing description to indicatethe scope of the invention.

The invention claimed is:
 1. A contact lens system, comprising: aperipheral conjunctival cover portion including a shell curved and sizedto substantially overly a conjunctiva of an eye and defining a fullthickness central opening therethrough, the central opening beingpositioned within the conjunctival cover and sized to expose at least aportion of a cornea of the eye; and a central contact lens portionpositioned at the central opening; wherein the central contact lensportion is coupled to the conjunctival cover portion by attachmentmembers.
 2. The contact lens system as claimed in claim 1, wherein thecentral contact lens portion is larger in diameter than the centralopening and partially overlies the conjunctival cover when on the eye.3. The contact lens system as claimed in claim 1, wherein the centralcontact lens portion is larger in diameter than the central opening andpartially underlies the conjunctival cover when on the eye.
 4. Thecontact lens system as claimed in claim 1, wherein the central contactlens portion is smaller in diameter than the central opening and fitswithin the central opening when on the eye.
 5. The contact lens systemof claim 1, wherein the attachment members are radially symmetricallyarranged.
 6. The contact lens system of claim 1, wherein the attachmentmembers are radially asymmetrically arranged.
 7. The contact lens systemof claim 1, wherein the central contact lens portion partially underliesthe conjunctival cover portion.
 8. The contact lens system of claim 1,wherein the central contact lens portion partially overlies theconjunctival cover portion.
 9. The contact lens system of claim 1,wherein the central contact lens portion is smaller in diameter than thecentral opening and is held within the central opening by the attachmentmembers.
 10. A method of treating an eye, comprising: applying aconjunctival cover to an eye; applying a central contact lens portion toan eye; and facilitating tear pumping by the relationship between theconjunctival cover portion and the central contact lens portion; whereinthe central contact lens portion is structurally joined to theconjunctival cover by attachment members.
 11. The method as claimed inclaim 10, wherein the central contact lens portion is structurallyjoined to the conjunctival cover and the method further comprisingapplying the central contact lens portion and the conjunctival cover tothe eye as a unit.
 12. The method as claimed in claim 10, furthercomprising selecting attachment members joining the central contact lensto the conjunctival cover to be symmetrically arranged whereby tearpumping is facilitated.
 13. The method as claimed in claim 10, furthercomprising selecting attachment members joining the central contact lensto the conjunctival cover to be asymmetrically arranged whereby tearpumping is facilitated.
 14. A method of treating an eye, comprising:applying a conjunctival cover to an eye; applying a central contact lensportion to an eye; and facilitating tear pumping by the relationshipbetween the conjunctival cover portion and the central contact lensportion; wherein the central contact lens portion is structurallyseparate from the conjunctival cover and the method further comprisingapplying the central contact lens portion to the eye prior to andpartially underlying the conjunctival cover.